In a semiconductor integrated circuit (IC), a power switch is used to selectively connect or disconnect a circuit block with/from a power supply. The semiconductor IC may have a plurality of power domains defined therein, and electrical components within the same power domain are driven by the same voltage power supply(s) and/or ground. Some of the power domains may be driven by a low-voltage power supply, and some of the power domains may be driven by a high-voltage power supply having a voltage higher than that of the low-voltage power supply. When a power switch is implemented to selectively bridge a circuit block with the high-voltage power supply, the electrical components, such as a Metal-Oxide Semiconductor Field Effect Transistor (MOSFET), of the power switch may be subjected to a large voltage drop. Thus, the electrical components of the power switch, compared with other electrical components not used as a part of the power switch, may have a higher level of oxide stress and current leakage. The higher level of oxide stress increases the risk of a transistor breakdown.